DS1685SN-3 Real Time Clock IC - Equivalent & Substitute Parts

Part Overview

The DS1685SN-3 is a Real Time Clock (RTC) IC with integrated Clock/Calendar functionality, manufactured by Analog Devices Inc./Maxim Integrated. This device provides timekeeping with alarm capability, non-volatile static RAM (NVSRAM), and square wave output in a 24-SOIC surface mount package. The DS1685SN-3 is classified as obsolete, making identification of active equivalent parts essential for new designs and ongoing production support.

Substiute Parts

DS1685SN-3

Analog Devices Inc./Maxim IntegratedIn Stock: 22710DS1685SN-3 Datasheet

Current PartRFQ

DS1685SN-3+

Analog Devices Inc./Maxim IntegratedIn Stock: 1156DS1685SN-3+ Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the DS1685SN-3 is determined by strict equivalence across the following critical parameters:

• Functional Type: Clock/Calendar RTC IC with identical feature set (Alarm, NVSRAM, Square Wave Output, Y2K)
• Memory Configuration: 242B memory size
• Time/Date Format: HH:MM:SS (12/24 hr) and YY-MM-DD-dd format support
• Interface: Parallel interface architecture
• Electrical Specifications: Supply voltage range 2.7V ~ 3.7V, battery supply 2.5V ~ 3.7V, timekeeping current 2mA @ 3V
• Operating Temperature: -40°C ~ 85°C range
• Package: 24-SOIC (0.295", 7.50mm Width) surface mount configuration

Only parts meeting all these parameters are classified as direct substitutes. Packaging format (Tube vs. other) does not affect functional equivalence.

Parameter Comparison

Engineering Selection Recommendations

The DS1685SN-3+ serves as the direct active equivalent to the obsolete DS1685SN-3. Both parts are manufactured by Analog Devices Inc./Maxim Integrated and maintain identical electrical, functional, and package specifications. The primary distinction is product status: DS1685SN-3 is obsolete while DS1685SN-3+ is active and currently in production.

For new designs and ongoing production requiring RTC Clock/Calendar functionality with parallel interface, the DS1685SN-3+ is the appropriate selection. The DS1685SN-3+ additionally carries ROHS3 compliance, providing enhanced environmental and regulatory alignment compared to the non-compliant DS1685SN-3.

Both parts share identical moisture sensitivity classification (MSL 1 - Unlimited) and REACH status, indicating equivalent handling and regulatory requirements.

Frequently Asked Questions (FAQ)

Q: Can DS1685SN-3+ be used as a direct replacement for DS1685SN-3 in existing designs?

A: Yes. The DS1685SN-3+ is a direct functional and electrical equivalent. All critical parameters—memory size, time/date format, interface type, supply voltage, operating temperature, and package configuration—are identical. Pin-for-pin compatibility is maintained.

Q: What is the significance of the product status difference (Obsolete vs. Active)?

A: The DS1685SN-3 is obsolete and no longer manufactured. The DS1685SN-3+ is the active production equivalent. For new designs, procurement, and long-term supply assurance, the DS1685SN-3+ is the appropriate choice.

Q: Does the RoHS compliance difference affect substitution?

A: The DS1685SN-3+ is ROHS3 compliant while the DS1685SN-3 is non-compliant. This difference reflects manufacturing process updates but does not affect functional equivalence. For applications requiring RoHS compliance, the DS1685SN-3+ is mandatory.

Q: Are there packaging differences between these parts?

A: Both parts use the 24-SOIC (0.295", 7.50mm Width) surface mount package. Packaging format (Tube for DS1685SN-3+) does not affect electrical or functional characteristics.

Q: What are the key parameters that determine substitution eligibility?

A: Substitution is determined by equivalence in: functional type (Clock/Calendar RTC), memory size (242B), time/date format support, parallel interface, supply voltage range (2.7V ~ 3.7V), battery supply range (2.5V ~ 3.7V), timekeeping current specification (2mA @ 3V), operating temperature range (-40°C ~ 85°C), and 24-SOIC package configuration.